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苹果枝枯病病原菌鉴定及生物学特性 总被引：1，自引：0，他引：1
正苹果(Malus pumila Mill.)是世界上栽培最为广泛的水果之一,由于其生态适应性强、营养价值高、耐贮性好及供应周期长,相当多的国家都将其列为主要消费果品[1],而我国是世界上苹果种植面积最大、产量最高的国家[2]。我国苹果枝干病害以苹果轮纹病和腐烂病为主,近年来随着气候环境的改变,一些新的病害也逐渐产生。2017年7月对烟台市几个苹果果园调查时,发现一种新病害。该病害主要危害苹果枝条,产生褐色坏死病斑,严重时导致枝条枯死,发 相似文献
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苹果枝枯病病原菌鉴定及生物学特性 总被引：1，自引：0，他引：1
In July 2017, a new shoot dieback disease, caused brown necrotic spots with black granules on the shoots in the late stage, was found in several apple orchards in Yantai, Shandong Province. The fungal pathogen was isolated on PDA plate from the infected shoots using the tissue isolation, which formed white to grey colonies bearing abundant fruiting bodies on Czapek solid media with lactose as carbon source. The purified fungal isolates La1-La3 were obtained from single spore isolation after spore tendrils exuding from pycnidia generated on the plates. This study was to identify and characterize the causal agent . Based on morphological characteristics and analysis of rDNA internal transcribed spacer (ITS), β-tubulin (TUB) and translation elongation factor 1-α (TEF1) nucleotide sequences, the fungal isolates were identified as Lasiodiplodia pseudotheobromae, a new pathogen on apple tree. The test of Koch's rule confirmed that L. pseudotheobromae was the pathogen of this disease. Effects of different temperature, pH value, carbon and nitrogen sources were tested against the growth of isolated fungus in vitro. The results showed that the optimal growth temperature and pH value were at 30℃ and pH 6-9, respectively, while the optimum carbon source was sucrose, and favourable nitrogen sources were sodium nitrate, ammonium nitrate and peptone. 相似文献
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为明确苹果炭疽叶枯病病原菌围小丛壳Glomerella cingulata的侵染致病特征,在分离获得该病原菌的基础上,采用形态学观察、ITS序列分析和致病性测定对其进行了鉴定,并利用光学和扫描电子显微镜对病原菌在嘎啦苹果叶片上的侵染过程进行了研究.结果表明,在陕西咸阳地区分离获得的9株病原菌均为围小丛壳G.cingulata.25 ℃下接种9 h后,分生孢子中间产生隔膜,双胞化,并萌发产生芽管和附着胞;24 h后分生孢子的2个细胞均可萌发并形成芽管及附着胞,部分芽管顶端可产生次级分生孢子;48 h后次级分生孢子萌发形成附着胞;72 h后,附着胞下形成的侵染钉可直接入侵寄主,在表皮细胞内形成初生菌丝和次生菌丝,此时叶片表面已出现褐色斑点.接种7 d后叶片病斑处出现分生孢子盘和子囊壳.表明陕西省近年出现的苹果炭疽叶枯病病原菌为围小丛壳G.cingulata,该病菌在嘎啦叶片上的一些特殊侵染行为可能是导致该病害易在短时间内暴发的重要原因. 相似文献
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In order to clarify the pathogen causing brown spot of Psidium guajava Linn., and provide a theore-tical basis for effective prevention and treatment of the disease, the pathogen of the brown spot of Psidium guajava Linn. was isolated and identified by molecular and morphological methods. The pathogen was obtained by tissue separation method, and the pathogenicity of the pathogen was determined by Koch′s rule. The morphological characteristics of the conidia of the pathogen were observed by optical microscope, and the sequence of the rDNA-ITS and RPB2 of the pathogen was analyzed by online Blast. The BLAST online alignment showed that the ITS sequence of the pathogen was 100% homologous with multiple strains of Alternaria alternata and Alternaria tenuissima, the homology of the RPB2 sequence of the pathogen with the strains of A. alternata and A. tenuissima reached 99.86%. According to the latest references, A. tenuissima (Fr.) Wiltshire was not an independent species but was a synonym of A. alternata (Fr.) Keissler. Combined with the pathological characteristics of pathogenic fungi, pathogenicity determination and phylogenetic tree analysis, the pathogen of guava brown spot disease in Guangdong was identified as A. alternata. 相似文献
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为明确猕猴桃黑点病的发生与果实矿质元素含量的关系,以期为黑点病的防治提供理论依据和指导方法,本研究通过测定病果与健果的果皮中主要矿质元素N、P、K、Ca、B、Mn,分析各矿质元素含量与发病的相关性,进而采取补施病果中显著缺乏的矿质元素,并测定补施后其对黑点病的预防效果。结果表明:2018—2019年,猕猴桃黑点病普遍发生,病园率高达100%。不同年份、不同果园“翠香”猕猴桃黑点病发病程度不同。通过对比病果与健果中矿质元素含量发现,病果皮中的N、B含量显著高于健果,Ca含量显著低于健果,并且病果皮中N/K、N/Ca、P/Ca和K/Ca比值显著大于健果,而Ca/B和Ca/Mn比值显著低于健果。连续两年田间补施Ca肥,对猕猴桃黑点病的预防效果可达到70%以上。猕猴桃黑点病的发生可能与果园管理中N、B过量以及Ca施用不足引起的矿质元素失衡有关。 相似文献
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华重楼斑枯病病原鉴定 总被引：1，自引：0，他引：1
2018年,四川汶川县重楼种植区的华重楼出现一种新的病害—华重楼斑枯病,该病害主要危害叶片,发生率为35%,天气适宜时可引起整株叶片枯死。为鉴定引起四川汶川县华重楼斑枯病的病原菌,本试验采用组织分离法对病原菌进行分离,利用科赫氏法则验证其致病性,依据菌株的形态学和基于rDNA-ITS和RPB2基因序列分析对病原菌进行鉴定。结果表明,分离菌株的菌落形态、分生孢子器和分生孢子形态与Didymella sp.相似;经分子生物学鉴定,该菌ITS-RPB2基因序列与亚隔孢壳属D. glomerata(登录号为FJ427013、GU371781)的同源性为100%。因此,将引起重楼斑枯病的病原菌鉴定为D. glomerata。 相似文献
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M. B. Spósito L. Amorim R. B. Bassanezi A. Bergamin Filho B. Hau 《Plant pathology》2008,57(1):103-108
Guignardia citricarpa , the causal agent of citrus black spot, forms airborne ascospores on decomposing citrus leaves and water-spread conidia on fruits, leaves and twigs. The spatial pattern of diseased fruit in citrus tree canopies was used to assess the importance of ascospores and conidia in citrus black spot epidemics in São Paulo State, Brazil. The aggregation of diseased fruit in the citrus tree canopy was quantified by the binomial dispersion index ( D ) and the binary form of Taylor's Power Law for 303 trees in six groves. D was significantly greater than 1 in 251 trees. The intercept of the regression line of Taylor's Power Law was significantly greater than 0 and the slope was not different from 1, implying that diseased fruit was aggregated in the canopy independent of disease incidence. Disease incidence ( p ) and severity ( S ) were assessed in 2875 citrus trees. The incidence-severity relationship was described ( R 2 = 88·7%) by the model ln( S ) = ln( a ) + b CLL( p ) where CLL = complementary log-log transformation. The high severity at low incidence observed in many cases is also indicative of low distance spread of G. citricarpa spores. For the same level of disease incidence, some trees had most of the diseased fruit with many lesions and high disease severity, whereas other trees had most of the fruit with few lesions and low disease severity. Aggregation of diseased fruit in the trees suggests that splash-dispersed conidia have an important role in increasing the disease in citrus trees in Brazil. 相似文献
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新病害—山核桃果实黑斑病病原菌的鉴定 总被引：1，自引：0，他引：1
2007年以来,浙江临安、淳安、桐庐和安徽部分地区山核桃主产区出现了一种果实新病害——山核桃果实黑斑病,该病严重影响山核桃果实的产量和品质。本研究从采集的病果中分离得到了一种真菌,离体幼果接种的症状与田间相似。病原菌在PDA培养基上形成白色轮纹状菌落,分生孢子长梭形,直或弯曲,(22.6～29.9)μm×(6.1～9.0)μm,5个细胞,中间3个有色孢(上部2个为黑褐色、下部1个为淡橄榄色),孢子顶生2～3根附属丝、多为3根。根据该病原菌的培养和形态特征及其ITS序列,将其鉴定为小孢拟盘多毛孢(Pestalotiopsis microspora)。 相似文献
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在广西香蕉种植区发现一种引起香蕉黑斑病的新病原。通过对病原菌分离培养、致病性测定、形态学观察、分子生物学鉴定及对该病原菌生物学特性进行初步研究,表明引起该病害的病原菌为芒果球座菌(Guignardia mangiferae A.J. Roy)。该病原菌菌落为深橄榄色,产生棒状子囊、梭形子囊孢子及倒梨形分生孢子;其最适生长温度为28℃,最适pH 值为6;病原菌生长较好的碳源为果糖和阿拉伯糖,氮源为蛋白胨和酵母膏;在全光条件下,病原菌菌丝扩展速度最快;菌丝的致死温度为54℃。由G. mangiferae引起的香蕉黑斑病,在国内外为首次报道。 相似文献